Glass is used for a variety of uses where it has a decorated or functional coating on it. One class of coatings is reflective coatings. These are typically 20 to 1,000 Angstroms thick films of metals such as copper, chromium, nickel, tin, iron, cobalt, silver and gold, or the oxides thereof, or various mixtures of such metals and oxides. Such coatings are applied to the glass by vacuum deposition, sputtering, chemical vapor deposition, thermal decomposition or pyrolysis of liquid spray solutions. Another set of coatings are opaque coatings. Such coatings are used to prevent the transmission of some or all light through the coated glass. Opaque coatings used commercially for many glass structures comprise ceramic coatings which are deposited on the glass. The ceramic coatings and glass are heated to 1,500° C. or greater to fuse the coating together and to the glass surface. Coated glass can be used for a variety of uses including for buildings. Some modern buildings utilize glass as a large part of the exterior façade. Often such glass has a reflective and or opaque coating disposed thereon. In one use the glass is reflective for aesthetic purposes. For buildings with a large amount of glass on the exterior, spandrel glass panels are utilized. Spandrel glass panels are opaque panels that cover parts of the building that are not aesthetically pleasant to view from the outside. These areas include floor slabs, plumbing, conduits for electricity and computer systems, heating and air conditioning ducts, structural beams and the like. Often these spandrel panels have bonded to the interior of the panels insulation materials. The opaque coating also hides such insulation or insulation panels and adhesive bonding them to the glass. Typically the reflective coating and the opaque coating are located on the interior side of the glass. In many buildings the glass which serves as windows having reflective coatings only so that the tenants can see out of the building. Where such buildings have both windows coated with a reflective coating and spandrel glass, it is desirable that the two look the same from the outside and that both have a reflective coating. Where the spandrel glass has a reflective coating, the reflective coating is located next to the glass and the opaque coating is placed on the reflective coating.
Mattimoe U.S. Pat. No. 4,302,503 discloses architectural spandrels which are reflective wherein a metal or metal oxide coating is placed on an inside surface of a sheet of glass by methods disclosed hereinbefore. Thereafter an opaque coating pigmented with carbon black is deposited on the reflective coating. The opaque coating comprises pigment in an alkyd based lacquer, paints based on pentaerythritols, polyurethanes, epoxies or acrylics may be employed. The coatings after drying can be contacted with adhesives to bond insulating panels to the glass panels.
Designers of coated glass articles desire to place on glass articles patterns, some of which are multicolored, which are aesthetic or communicate important information, such as trademarks, the source of the product or important information about the product. The process for applying ceramic coatings to glass make it difficult or cost prohibitive to apply multicolored designs or informational graphics on glass articles.
The high temperatures necessary to cure these ceramic coatings are undesirable due to the large amount of energy required and the stress placed on the glass by the coating fused on the glass which can result in glass breakage. Additionally, an inorganic ceramic coating fused into the glass makes it difficult to recycle the glass when there is a defect in the glass which occurs during manufacture of the glass or at the end of life of a vehicle. The coatings disclosed in Mattimoe have not found significant commercial use as spandrel glass is commercially produced by use of ceramic based coatings and high temperature fusing processes.
What is needed is a coating for glass which can be applied without the need for very high curing temperatures, which can bond to standard adhesives and which facilitates recycling of the glass. What is also needed is a coating system that allows application of multicolored and/or information coatings on glass articles.